• Korean Journal of Food Science and Technology
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• v.31 no.3
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• pp.586-592
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• 1999

The objective of this study was to investigate the fundamental characteristics of proteins effecting on Korean wheat flour quality. Mixing properties and protein contents of Eunpa, Allgreu, and Woori showed soft wheat characteristics. Tapdong had strong dough stability and high protein content like hard wheat flour. However, even though Greu had a high protein content, the dough strength was very weak like soft wheat flour. No major difference was observed in protein solubility with water, 0.1N NaCl, 70% ethyl alcohol, 0.1 N acetic acid solution and in sulfur and disulfide contents between Korean wheat flours and imported flours. However, DNS (Dark Norther Spring) had more contents of acid insoluble and SDS insoluble proteins compared with Korean wheat varieties. PAGE pattern of Tapdong was very similar to imported wheat flours at the high molecular weight regions and characteristic high molecular weight glutenin subunits were observed over 116 kD protein molecular weight region from 4 Korean wheat flours such as Eunpa, Woori, Allgreu, and Greu.

• Research in Plant Disease
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• v.13 no.1
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• pp.34-39
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• 2007

Lichen thalli of Dirinaria applanata heavily colonized on the twigs of dead or dying Rhododendron trees in Solok island, Jeonnam province in Korea. Pathogenesis of the lichen on the trees was investigated to find out the possibility of lichen as a causal agent. Histological examination of the lichen colonized twigs was attempted with differential staining technique. Lichen-forming fungus colonized only on the surface of bark and there was no direct penetration of fungal hyphae into the plant tissues. Symbiotic algae of the lichen was also examined. The isolated algal cells were inoculated on artificially induced wounds of the healthy trees. Histological examination of the inoculated tissues showed that some algal cells were successfully colonized inside the tissues without any pathogenic symptoms, even 2 months later, The extract of the lichen thalli was also examined using 10% of DMSO solution. Treated tissues showed no pathogenic symptoms, even 4 weeks later. The results suggested that the lichen was not directly involved in the death of the trees.

• Applied Biological Chemistry
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• v.34 no.4
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• pp.373-378
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• 1991

The skin and fleshy substance on the net fiber of sponge-gourd fruit pressed mechanically was removed with 0.2% NaOH solution in $3{\sim}5$ hours. The treatment of 0.2% NaOH with 0.02% Monopol(non-ionogenic polyoxethylen derivative) as surfactnat and with 0.1% $Ca(OCl)_2$ as bleaching agent enhanced the effect to remove the fleshy substance and improve the quality of net fiber. Also, the wet hardness and tensile strength of net fiber were controlled by the crosslinkage of the fiber with glu tardialdehyde, glyoxal, and formalin, respectively. The net fiber was stable on the acid and alkaline solutions. Also the range of temperature to degradate the fiber was $338{\sim}385^{\circ}C$. These values indicated a fair stability. The improved net fiber can be used for raw material of bath, dish washing, oil and gas filter, and many kinds of decorations.

• Journal of the Korean GEO-environmental Society
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• v.10 no.6
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• pp.61-68
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• 2009

The main objective of this study was to examine the removal of heavy metals from water by inflated vermiculites. The component of vermiculites was analyzed by XRF, and the concentration of metal ion was measured by ICP-AES. Serial batch kinetic tests and batch sorption tests were conducted to determine the removal characteristics for heavy metals in aqueous solutions. As a result, solution pH values of tests with the inflated vermiculites generally increased and then stabilized. Equilibrium pHs were generally established within 5 hrs. In addition, removal rates of inflated vermiculites were tested at the initial concentration of 3 mg/L. As a result, at equilibrium concentration, except for chromium (36.23%), Most of the heavy metals were effectively removed (96.08~98.54%). Finally, sorption data were correlated with both Langmuir and Freundlich isotherms. The Qmax obtained from Langmuir isotherm were determined to Pb $725.4mg\;kg^{-1}$, Cd $568.8mg\;kg^{-1}$, Zn $540.2mg\;kg^{-1}$, Cu $457.2mg\;kg^{-1}$ Cr $0.9mg\;kg^{-1}$ respectively. The results of the study indicate that inflated vermiculites can be properly used as an adsorbent for various heavy metals because of its outstanding removal rate.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.4
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• pp.356-360
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• 2000

In order to utilize the processing wastes of squid, chitosan was prepared by intermittent deacetylation treatment of ${\beta}-chitin$ richly contained in the pen of squid, and then their characteristics of chitosan and N-acetylchitosan film were studied. The acetylation time of N-acetylchitosan film-1 (N-ACE-1) manufactured from chitosan solution by treating with acetic anhydride was about 12 hrs. In SEM photomicrographs, the surface of chitosan film was regularly arranged netlike, and that of N-acetylchitosan film-2 (N-ACE-2) was rough like snowflake and larger than chitosan film. The chitosan film (thickness 0.02 mm, time 60 min) had the highest tensile strength ($1,240 kg/cm^2$) and elongation ($58.25{\%}$), N-ACP-1 (thickness 0.02 mm, time 60 min) had the highest water permeability ($539 g/m^2{\cdot}24 hrs$), oxygen permeability ($20,000 cm^3/m^2{\cdot}24 hrs{\cdot}atm$) and water uptake ($350{\%}$) among the tested films.

• Clean Technology
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• v.14 no.2
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• pp.110-116
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• 2008

The radioactive wastes generated from the nuclear industry can be divided into the forms of solid, liquid, or gas. Radioactive methyl iodide, a gaseous radioactive waste, is absorbed by activated carbon with 5 wt% of Trietylenediamine (1,4-diazania-bicycle[2.2.2]octane, TEDA) impregnated on the surface. Methyl Iodide ($CH_3I$) is combined chemically with TEDA (the final product : I-TEDA). To recycle radioactive activated carbon, removal of I-TEDA from activated carbon is needed. A wet method for recycling impregnated active carbon was developed to remove radioactive I-TEDA using an acetonitrile solution, which produces lots of secondary wastes. We suggest the removal of I-TEDA by supercritical carbon dioxide with co-solvents. In this experiment, we used a quartz crystal microbalance (QCM) for measuring the removal rate of the I-TEDA. From the experimental results, methanol was found to be the optimum co-solvent, and the optimum conditions such as temperature, pressure, and co-solvent flow rate were obtained. Possibility of using supercritical fluid in the removal of I-TEDA from radioactive activated carbon was also discussed.

• Membrane Journal
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• v.20 no.4
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• pp.304-311
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• 2010

In this study, loose RO hollow fiber membranes using CTA polymer were prepared by phase inversion method and their water purification properties were tested. 1,4-dioxane and LiCl was used as a skin layer formation agent and pore formation agent, respectively. Water flux, salt rejection, chlorine resistance, MWCO and membrane morphology were evaluated as a function of the dope composition. When the membrane prepared using the dope solution of CTA/NMP/1,4-dioxane = 18/72/10 (wt%) with air gap of 30 cm, it shows improved RO performance such as $20.5L/m^2hr$ of water flux, 60% of NaCl rejection, 10,000 ppm/hr of chlorine-resistance and around 5,000 Da of MWCO.

• Journal of the Mineralogical Society of Korea
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• v.18 no.3 s.45
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• pp.183-194
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• 2005

The mineralogical, physicochemical and thermal properties of the Myogi bentonite occurring in Japan were measured. A adsorption properties of U, Th, Ce and Eu ions on the Myogi bentonite were also investigated in different solution concentrations and pH conditions. The Myogi bentonite showed a strong alkaline character (pH 10.4), very high swelling, viscosity property and CEC, and a slow flocculation behavior due to the strong hydrophilic property. By the thermal analysis, the dehydroxylation of crystal water in bulk and clay fractions of the Myogi bentonite occur at $591^{\circ}C$ and $658^{\circ}C$, respectively, The adsorption experiments of ions such as U, Th, Ce and Eu were conducted for 0.2 g bentonites with 20mL solutions of various concentrations and different pH conditions with pH 3, 5, 7, 9, and 11. As a result, the Myogi bentonite showed excellent adsorption capacities for Ce, Th and Eu ions, whereas U ion showed very low adsorption capacity. Generally, Ce, Th and Eu ions showed the similar adsorption properties for the different concentrated solutions and pH conditions. These adsorption properties seem to be affected by the formation of various forms of chemical species and precipitation as well as ionic exchange reaction and surface adsorptions on smectite. Some associated zeolite minerals perhaps have some effects on the adsorption of U, Th, Ce and Eu on Myogi bentonite.

• Journal of the Korean Chemical Society
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• v.39 no.6
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• pp.459-465
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• 1995

Acetolactate Synthase (ALS) was partially purified from the yeast and its basic biochemical studies were carried out. Yeast was grown in the minimum media containing 0.5% glucose, 51 mM $K_2HPO_4$, 22 mM $KH_2PO_4$, 8 mM $(NH_4)2SO_4,\;0.4\;m M\;MgSO_4$ for 18 hours at 37 $^{\circ}C$. The cell was ruptured in the buffer (20 mM phosphate buffer pH 7.0, 0.1 mM TPP, 0.5 mM DTT, 1 ${\mu}M$ FAD, and 1 mM MgCl_2$) following an overnight suspension. The supernatant fraction was collected from $10,000{\times}g$ and the enzyme was further purified by ammonium sulfate fractionation, DEAE-Sephacel chromatography and leucine-agarose chromatography. The enzyme activity was measured under the various conditions by the function of protein concentration, time, temperature, pH, and substrate. The optimum temperature was found to be 50$^{\circ}C$, optimum pH 8.0∼8.5. The kinetic parameters, $K_m\;and\;V_{max}$ were 8.4 mM and 17.9 nmol/mg/min respectively. Stability of the enzyme was studied with ethylene glycol and glycerol added to the enzyme solution. Both ethylene glycol and glycerol improved the enzyme stability up to 50%. The study of feedback inhibition showed that valine was a strong inhibitor while leucine was a weak inhibitor.

• Journal of the Earthquake Engineering Society of Korea
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• v.11 no.6
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• pp.1-14
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• 2007

Optimal design method of nonlinear damping system for seismic response control of adjacent structures is studied in this paper. The objective functions of the optimal design are defined by structural response and total amount of the dampers. In order to obtain a solution minimizing two mutually conflicting objective functions simultaneously, multi-objective optimization technique based on genetic algorithm is adopted. In addition, stochastic linearization method is embedded into the multi-objective framework to efficiently estimate the seismic responses of the adjacent structures interconnected by nonlinear hysteretic dampers without performing nonlinear time-history analyses. As a numerical example to demonstrate the effectiveness of the proposed technique, 20-story and 10-story buildings are considered and MR dampers of which hysteretic behaviors vary with the magnitude of the input voltage are considered as nonlinear hysteretic damper interconnecting two adjacent buildings. The proposed approach can provide the optimal number and capacities of the MR dampers, which turned out to be more economical than the uniform distribution system while maintaining similar control performance. The proposed damper system is verified to show more stable performance in terms of the pounding probability between two adjacent buildings. The applicability of the proposed method to the design problem for optimally placing semi-active control system is examined as well.